Device for providing communication between water tanks of heat accumulation tank system

ABSTRACT

Disclosed is a heat accumulation tank system intended for use as a heat source of, for example, an air conditioner and which is installed, for example, in a building or under a green zone, a stadium or a parking area. The heat accumulation tank system is composed of a pularity of water tanks which are connected through a communication passage such as a communication pipe. The pressure in the communication passage is controlled by means of a pressurizing device or a vacuum device, so that the state of communication is controlled such as to establish or interrupt the communication between the water tanks or to control the rate of flow of water between these water tanks.

DESCRIPTION

1. Field of the Invention

The present invention relates to a device for providing communicationbetween a pair of adjacent water tanks in a heat accumulating water tanksystem. More particularly, the present invention is concerned with adevice for providing communication between a pair of water which areadjacent to each other in a heat accumulation water tank system which isinstalled in a building or under a green zone, a stadium or a parkingarea and which is sectioned into a plurality of water tanks by means ofpartition walls.

2. Background Art

The current tendency for better living conditions has given a rise tothe demand for air conditioning, as well as for hot water runningservice and running service of cooling water for cooling machines. Inparticular, buildings designed for business activities consume muchenergy because of cooling load which is increased as a result of heatgeneration from various machines such as computers and other officemachines. In order to reduce the level of peaks of thermal load andelectrical power consumption, while attaining a higher economy byutilization of electrical power available at midnight, buildingsintended for business use and other large-scale buildings are equippedwith heat accumulating water pools or tanks. In some cases, area-wideair-conditioning systems are adopted for conditioning air in a wide areaincluding a plurality of buildings, by employing a water pool or tanksystem.

Usually, a heat accumulation water tank, i.e., heat accumulation tank,is sectioned into a plurality of water tanks by means of partitionwalls, for the purpose of improving the heat accumulation effect throughsmoothing the circulation of water in the tank system and for thepurpose of attaining a higher strength of the tank. In order toefficiently conduct air conditioning by making use of water in the heataccumulation tank system, it is necessary that the amount of water to beheated or cooled is suitably controlled in accordance with the seasonalvariation in the demand for air conditioning. To cope with such ademand, the water tanks of a heat accumulating tank system are groupedinto a plurality of blocks each including one or more water which aremutually connected, the adjacent blocks being communicated with eachother through communication passages which can be opened and closed asdesired. In operation, the communication passages are selectively openedand closed so that these blocks of water tanks are selectively put intopractical use in such a manner that only a single block is used or aplurality of blocks are used in combination, thereby optimizing theamount of water to be heated or cooled for the purpose of airconditioning.

It is also to be pointed out that the heat accumulating tank system hasto be periodically drained for the purpose of inspection of the interiorand replacement of water. Preferably, this is conducted by draining someof the blocks while other blocks are operating under ordinary operatingconditions, so that the successive blocks of tanks are sequentiallydrained and inspected. The communication passages between the blockshave to be opened and closed also for this purpose.

Conventionally, the means for seelectively opening and closing thecommunication passage employs a mechanical valves such as a slide-typeshut-off valve or a butterfly valve. These valves are usually operatedby a valve actuator which is installed on the upper side of the tank soas to be moved up and down or rotated thereby opening and closing thecommunication passage.

The valve mechanism used conventionally thus requires a large space foraccommodating a valve actuating mechanism which is installed on an upperpart of the tank. In addition, maintenance work has to be executedfrequently for maintaining good conditions of the valve and the valveactuating mechanism. For instance, in the case of a slide-type valve, itis necessary to lift the valve member to open the communication passage,so that a space large enough to accommodate the valve member has to bepreserved on the upper side of the heat accumulating tank. On the otherhand, when a butterfly valve is used, the have shaft has to be extendedupward to project from the tank and a valve operating handle has to beattached to the extended portion of the valve shaft. Obviously, thethermal load on the air conditioner is increased as the scale of thebuilding is increased, and the heat accumulating tank also becomesgreater. This requires the size of the of the valve in the communicationpassage and, hence, of the mechanism for actuating the valve, with theresult that a large space is required for the maintenance work. Inconsequence, the area for lent on the floor immediately above the heataccumulating tank or the area of the machine room or parking area isreduced uneconomically.

The conventional valve mechanisms suffer a problem in regard to thedurability. Namely, the temperature of the water in the heataccumulating tank is usually maintained at about 5° to 10° C. duringcooling of air and at about 50° to 60° C. during heating. The valvemember, valve seat and seal members of the valve mechanism are left inwater for a long period of time, so that the problems are caused such asdeterioration of the valve member and the sealing member, rusting ofmovable parts, stick of the sealing member, and leak through the valve.In consequence, works such as renewal of the sealing members andmaintenance of the sliding parts of the valve have to be conductedrather frequently. These works are laborious and require much time andmoney. In some cases, water pooled in the tank system has to be wasted.

DISCLOSURE OF THE INVENTION

Accordingly, a primary object of the present invention is to overcomethe above-described problems concerning the communication passages inthe heat accumulation tank system.

Thus, a practical object of the present invention is to provide a devicefor providing communication between water tanks in a heat accumulatingwater tank system which is capable of selectively opening and closingcommunication passage between water tanks while requiring only a smallinstallation space, and which exhibits superior durability due toelimination of any movable part.

In order to meet these demands, the present invention proposes toselectively open and close the communication between two water tanks ofa heat accumulation tank system, by suitably controlling the pressure inthe communication passage.

According to one form of the invention, there is provided a device forproviding communication between two adjacent water tanks in a heataccumulating tank system having a plurality of water tanks which areseparated by partition walls, comprising a control chamber connected toone of two adjacent water tanks, the control chamber being closed atleast upper side thereof, and a rising passage opens into the controlchamber. The rising passage has one end which opens into the other oftwo adjacent water tanks while the other ends rises in the controlchamber so as to level in the water tank. A vacuum suction means isconnected to the upper space in the control chamber through a valvemeans.

In another form of the present invention, an inverse U-shaped passage isconnected between two adjacent water tanks such that one end thereof isopened into one of two adjacent water tanks while the other end opensinto the other of two water tanks, and the pressure in the upper portionof the inverse U-shaped passage is controlled by means of pressurecontrol means.

In still another form of the present invention, a control tank isdisposed in one of two adjacent water tanks, and the control tankaccommodates a rising pipe having one end opened to the exterior of thecontrol tank at a level below the normal water level in the one of twoadjacent tanks and the other end rising in the control tank so as toopen at the upper end in an upper portion of the control chamberFurthermore, the control chamber is connected to the other of the twoadjacent water tanks, and a pressure control means is provided forcontrolling the pressure in the upper portion of the control chamber.

In a modification of this form of the invention, the interior of thecontrol chamber disposed in one of the two water tanks is divided bypartitioning means into a first chamber and a second chamber whichcommunicate with each other at their upper portions, the first chambercommunicating with one of the two water tanks while the second chambercommunicates with the other of two water tanks.

In still another form of the present invention, passage forming meansprovides an inverse U-shaped communication passage which is disposed tobridge over the partition wall separating two adjacent water tanks so asto provide a communication between these water tanks across thepartition wall. The space in the upper portion of the U-shaped passageis connected to a vacuum suction means through a valve means.

In any one of these forms of the invention, the pressure control meansor the vacuum suction means may be substituted by a pressurizing/suckingmeans which is capable of effecting pressurizing of communicationpassage for providing the communication and sucking for the purpose ofbreaking the communication.

In the communication control device of the invention, the end of thecontrol chamber opening into the control chamber is disposed such thatthe end of the passage opening in the control chamber is positioned at alevel above the normal water level in the water tank. Therefore, thecommunication between two adjacent water tanks is interrupted whenvacuum is not introduced into the upper portion of the control chamberAs vacuum is introduced into upper portion of the control chamber, thewater level in the control chamber rises and, when the water level hasreached to a feel above the open end of the passage in the controlchamber, two water tanks are brought into communication with each otherthrough the control chamber

In the second form of the present invention, when the mid portion of theinverse U-shaped passage is positioned above the normal water level inthe water tank, air stagnates in the mid portion of the inverse U-shapedpassage so that the communication between two water tanks isinterrupted. However, when the vacuum is applied to the mid portion ofthe inverse U-shaped passage, the water level in the passage rises tosuck water into the inverse U-shaped passage, so that a communication isestablished between two water tanks through the inverse U-shapedpassage. When he mid portion of the inverse U-shaped passage is belowthe normal water level in the water passage, water is allowed to fillthe inverse U-shaped passage even in normal state, thus maintainingcommunication between two water tanks. Conversely, when a positivepressure is applied to the mid portion of the passage, the communicationis interrupted. The manners of operation of the communication controldevice in other forms are materially the same as those described above.

When pressurizing/sucking means is used for the purpose of the pressurecontrol, the communication between two water tanks is interrupted whenpositive pressure is applied to the control chamber or the inverseU-shaped passage, and the communication is established when negativepressure is applied to the same. This form is advantageously adoptedwhen the distance between the normal water level in the water tank andthe top wall of the water tank is small.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of an embodiment of the device in accordancewith the invention for providing communication between water tanks;

FIG. 2 is a schematic illustration of operation of the device shown inFIG. 1;

FIGS. 3 to 6 are views similar to FIG. 2 but showing differentembodiments of the invention;

FIG. 7 is a sectional view of a further embodiment of the presentinvention;

FIG. 8 is a sectional view taken along the line VIII--VIII of FIG. 7;

FIG. 9 is a sectional view of a still further embodiment of the presentinvention;

FIG. 10 is a sectional view taken along the line X--X of FIG. 9;

FIG. 11 is a schematic sectional view of a modification of theembodiment as shown in FIG. 7;

FIG. 12 is a sectional view of a modification of the embodiment shown inFIG. 4;

FIGS. 13 to 17 are schematic sectional views of different embodimentscorresponding to FIGS. 2 to 6;

FIG. 18 is a plan view of an embodiment of the heat accumulation tanksystem to which the present invention is applied; and

FIGS. 19 to 24 are schematic illustrations of the states of use of theheat accumulation tank system in different seasons.

THE BEST MODE FOR CARRYING OUT THE PRESENT INVENTION

Embodiments of the communication control device of the present inventionwill be described hereinunder.

FIG. 1 shows a communication control device 2 which is provided betweena pair of adjacent water tanks 1, 10 constituting a heat accumulationwater tank system. The communication device 2 is constituted by abox-shaped housing 5 which is provided therein with a control chamber 24and with an inlet 3 and an outlet 4 at the left and the right sidesthereof. The housing 5 is placed on a support fixed on the bottom of thewater tank 1. The housing 5 has a pipe 7 which is formed integrallytherewith and extending therefrom so as to communicate with the inlet 3.A connection flange 8 is formed on the end of the pipe 7. A connectionflange 12 of a communication pipe 11 is connected to the flange 8. Thewater tanks 1, 10 are separated from each other by a partition wall 9,and the aforementioned communication pipe 11 is supported by thepartition wall 9. The communication pipe has one end opened to theinterior of the water tank 10, thus constituting a passage through whichthe interior of the water tank 10 is connected to the control chamber24. A riser pipe 13 is provided in the housing 5 so as to rise upwardfrom the outlet 4. The pipe 13 has an end which opens in the controlchamber 24 at a level which is higher than the upper brims of the inlet3 and the outlet 4 and which is higher than the water level WL obtainedin the water tanks 1, 10 in the normal state of use. The end 14 of thepipe 13 is supported on the housing 5 by means of a plurality of radialsupports 15 so as to prevent the riser pipe 13 from oscillating by theforce of the fluid.

A gas passage 16 is attached to the upper wall of the housing 5. The gaspassage 16 is communicated with a vacuum pump 17. A solenoid valve 18 isinterposed between the vacuum pump 17 and the gas passage 16 A gaspassage 19 shunts from a portion between the housing 5 and the solenoidvalve 18. This gas passage opens to the atmosphere through a stop valve20. A liquid level meter 21 for detecting the liquid level in thecontrol chamber 24 is secured to the upper wall of the housing 5. Thisliquid level meter 21 is an electrostatic capacitive level meter havingan electrode 22 inserted into the control chamber 24 at the exterior ofthe riser pipe 13. The output terminal of the liquid level meter 21 isconnected to the input terminal of the liquid level controller 23 theoutput of which is connected to a solenoid valve 18. The operation ofthis communication control device will be explained herein under withreference to FIG. 2. In order to establish the communicating state ofthe communication device, the valve 20 is closed and the solenoid valve18 is opened and closed in accordance with the level in the controlchamber 24. When the solenoid valve 18 is opened, negative pressure isintroduced into the control chamber 24 from the vacuum pump 17 throughthe gas passage 16. In consequence, the water level H in the housing 5is raised to a level above the level of the end 14 of the riser pipe 13,whereby two adjacent water tanks 1, 10 are brought into communicationwith each other. The state of the solenoid valve 18 is controlled inresponse to the result of detection of the water level H in the controlchamber 24 so as to maintain the communication.

Conversely, in order to interrupt the communication between the watertanks 1, 10, the valve 20 in the gas communication pipe 19 is opened andthe solenoid valve 18 is closed. As a result, atmospheric pressure isintroduced into the control chamber through the gas passage 16, wherebythe water level in the control chamber 24 is lowered to the same levelWL as the water tanks 1, 10, thus interrupting the communication betweenthe water tanks 1, 10.

The liquid level meter 21 and the liquid level controller 23 in thiscommunication control device operate to maintain the liquid level in thecontrol chamber 24 above the level of the end 14 of the riser pipe 13.To this end, the electrode 22 of the liquid level meter 21 is sodesigned as to be able to detect two reference levels which are setbeforehand, and the solenoid valve 18 conducts a control such that theactual liquid level is always maintained between two reference levelseven in the case of the fall of the liquid level due to leakage from thegas passage.

In this embodiment, if it is not allowed to preserve a sufficientlylarge distance between the normal water level L and the top walls of thewater tanks 1, 10, the end 14 of the riser pipe 13 cannot project by asufficient height from the water level in the water tanks 1, 10, so thatthe device may fail to maintain the shut-off state. In such a case, theend 14 of the riser pipe 13 may be positioned substantially at the samelevel as the normal liquid level WL in the water tanks 1, 10, and thevalve 20 is constituted by a solenoid valve, and a compressor 17a isconnected to the solenoid valve 20 as shown in FIG. 2. For the purposeof interrupting the communication between two water tanks 1, 10, thesolenoid valve 18 is closed and the solenoid valve 20 is actuated toallow the compressed air to be introduced into the control chamber 24.As a result of this control, the water level in the control chamber 24is lowered to a level L which is lower than the water level WL in thewater tanks 1, 10, so that the end 14 of the riser pipe 13 is maintainedsufficiently above the water level L in the control chamber 24, therebyto ensure the shut-off of the communication between two water tanks. Forthe purpose of recovering the communication between two water tanks 1,10, the solenoid valve 20 is closed and the solenoid valve 18 isoperated. As a result of this control, the water level H in the controlchamber 24 rises to a level which is sufficiently higher than the end 14of the riser pipe 13, whereby the communication is established. Thecontrol of the liquid levels H, L in the control chamber 24 can beeffected by the liquid level controller 23 which is suitably switchedbetween the communicating condition and the shut-off condition. FIGS. 3to 6 show different embodiments of the present invention.

The communication control device 3 as shown in FIG. 3 has a housing 5installed in the water tank 1 and a pipe 7 connected to the water tank10 rises in the control chamber 24 thus constituting a riser pipe 25. Asis the case of the riser pipe 13 in FIG. 2, the riser pipe 25 extendsupward to a level which is above the normal water level WL in the watertanks 1, 10. A pipe 26 opening into the water tank 1 is secured to theside wall of the housing 5 at a level below the upper end of the riserpipe 25.

The communication control device shown in FIG. 4 has a riser pipe 25similar to that in FIG. 3. In this device, however, the housing 5 isconstructed in the form of a hood which is opened at its lower side Inthis embodiment also, the upper end of the riser pipe 25 opens into thecontrol chamber 24 at a level above the water level in the water tanks1, 10.

The communication control device shown in FIG. 5 employs a partitionwall 28 in place of the riser pipe 25 shown in FIG. 3. The upper end ofthe partition wall 28 is positioned above the levels of the upper edgesof the inlet 3 and the outlet 4 of the housing 5 and also above thenormal water level WL in the water tanks 1, 10. The partition wall 28divides the control chamber 24 in the housing 5 into two chambersnamely, chambers 24a and 24b. These chambers 24a and 24b communicatewith each other at their upper portions The communication chamber 24a isconnected to the water tank 10 through the inlet 3, while the chamber24b communicates with the water tank 1 through the outlet 4.

In each of the embodiments shown in FIGS. 3 to 5, the space in the upperportion of the control chamber 24 is connected to a vacuum pump (notshown) through a valve, as in the case of the embodiments shown in FIGS.1 and 2. The control of the communication and shut-off of the watertanks 1, 10, therefore, is conducted in the same manner as that in theembodiments shown in FIGS. 1 and 2. In each of the embodiments shown inFIGS. 1 to 5, if the water tanks 1, 10 store water of differenttemperatures, the water of different temperatures is introduced into theriser pipe and the control chamber, so that it is necessary that asuitable heat-insulating member is provided on the walls of the housing,and the passage between the water tanks 1, 10.

The embodiments shown in FIGS. 3 to 5 may be modified such that thecontrol of the pressure in the control chamber 24 is conducted by thecombination of a compressor and a vacuum pump as described before.Obviously, the communication between the water tanks 1, 10 isinterrupted when compressed air is introduced into the control chamber24 from the compressor, whereas the communication is established whenvacuum is introduced into the control chamber.

In the embodiment shown in FIG. 5, the communication control device isconstituted by an inverse U-shaped pipe 29 which is provided in such amanner as to bridge over the partition wall 9 which separates both watertanks 1, 10. Both end portions of the inverse U-shaped pipe 29 arecurved downward within the water tanks 1, 10 so as to open to the bottomin the water tanks 1, 10. The inverse U-shaped pipe 29 is installed suchthat its mid portion 30 is positioned at the highest level. Thus, theintermediate passage 31 constituted by this intermediate portion 30 ispositioned above both end portions.

The inverse U-shaped pipe 29 is positioned below the level WL in thewater tanks 1, 10, while the intermediate passage 31 is positioned abovethe water level WL. The gas passage 16 is connected to this intermediatepassage 31. Usually, the solenoid valve 18 is kept open while the valve20 in the gas passage is closed, so that the water level has risen tothe level H shown in FIG. 6 so as to enable the water to fill theintermediate passage 31, thereby providing communication between thewater tanks 1, 10. As the valve 20 is opened while the solenoid valve18, the intermediate passage 31 is filled with air, so that thecommunication between adjacent water tanks 1, 10 is interrupted. Apressure controller 33 is connected to the gas passage 16. A solenoidvalve 18 is connected to the pressure controller 33. The pressurecontroller 33 incorporates a vacuum gauge the output of which is used incontrolling the solenoid valve 18 such that the vacuum is introducedinto the gas passage 16 from the vacuum pump 17 thereby to maintainvacuum of a predetermined level in the gas passage 16. In thiscommunication control device, when it is designed to allow the water tofill the gas passage 16, the state of communication is preferablydetected by means of a pressure gauge as in this embodiment, rather thanby a level meter. In this embodiment, the communication control deviceis constituted by an inverse U-shaped pipe and the intermediate passageprovided by the inverse U-shaped pipe is located above the normal liquidlevel in the water tank. This advantageously eliminates the necessityfor any water-tight seal between the inverse U-shaped pipe and thepartition wall. When the communication control device is constituted byan inverse U-shaped passage such as an inverse U-shaped pipe, the spacein the inverse U-shaped passage is filled with air when thecommunication is to be shut-off, so that the disconnection between twoadjacent water tanks is safely maintained by the air, with the resultthat the loss of heat is minimized even when the water temperatures inboth tanks are different. This advantageously eliminates the necessityfor the provision of heat-insulating material on the inverse U-shapedpipe and other members. In the embodiment of FIG. 6 also, thearrangement may be such that the intermediate passage 31 constituted bythe intermediate portion 30 of the inverse U-shaped pipe 29 ispositioned substantially at the same level as the normal water level WLin the water tanks 1, 10, with the help of means for pressurizing andevacuating the intermediate passage 31 for the purpose of interruptionand establishment of the communication.

FIGS. 7 and 8 show an embodiment in which the inverse U-shaped passageequivalent to that of FIG. 6 is constituted by the top walls of thewater tanks. Referring to FIG. 7, two water tanks 1, 10 are separatedfrom each other by a partition wall 9, and the upper end of thepartition wall 9 is so sized that a predetermined gap is left betweenits upper end and the top wall 9a of the water tanks. The top wall 9ahas a passage forming wall 50 adjacent to the water tank 1 and a passageforming wall 51 adjacent to the water tank 10. These passage formingwalls are disposed on both sides of the partition wall 9 so as to extenddownward The passage forming walls 50, 51 cooperate with the partitionwall 9 in forming an inverse U-shaped passage 52 which has anintermediate portion above the normal water level WL in the water tanks1, 10, while both ends thereof open downward in the respective watertanks 1, 10 at levels below the normal water level WL in the water tanks1, 10. The top wall 9a of the water tank has a gas passage connectingpipe 53 which opens to the passage 52. A gas passage 16 similar to thatin each of the described embodiment is connected to the gas passageconnecting pipe 53. When the upper end of the partition wall 9 is abovethe normal water level WL in the water tanks 1, 10 as in the illustratedembodiment, the gas passage 16 is connected to the vacuum pump throughthe solenoid valve. When this solenoid valve is opened, vacuum isintroduced into this passage 52 so that water rises in the passage 52 soas to bring both water tanks 1, 10 into communication with each other.When the arrangement is such that the upper end of the partition wall 9is below the normal water level WL in the water tanks 1, 10, i.e., whenso-called underwater-dam type structure is employed, the gas passage 16is connected to a compressor through a solenid valve so as to besupplied with compressed air through the solenoid valve thereby tointerrupt the communication between both water tanks 1, 10. Theelectrode 22 of the liquid level meter 21 is inserted into the passage52 through the gas passage connecting pipe 53 so that the water level inthe passage 52 is detected by the liquid level meter 21.

FIGS. 9 and 10 illustrate a case in which the inverse U-shaped passageis detachably secured to the top wall of the water tanks. In thisembodiment, the top wall 9a disposed above the partition wall 9 has anopening 9b and a cover 60 is provided in such a manner as to close theopening 9b. A passage forming member 61 having an inverse U-shapedpassage 62 is provided on the underside of the cover 60. The passageforming member 61 is so disposed that it bridges over the partition wall9 when the cover 60 closes the opening 9b. When the passage formingmember is installed at this position, the inverse U-shaped passage 62 ispositioned above the water level in the water tanks 1, 10, with bothends thereof opened downward in the respective water tanks 1, 10 at alevel below the water level. As in the case of the embodiment shown inFIGS. 7 and 8, this embodiment also has a gas passage connecting pipe 63connected to the inverse U-shaped passage 62. In this embodiment, theconnection pipe 63 is formed as a unit with the passage forming member61 A gas passage 16 is connected to the connecting pipe 63. An electrode22 of the liquid level meter 21 extends through the connecting pipe 63into the passage 62.

FIG. 11 illustrates a modification of the embodiment shown in FIG. 11.As will be seen from this Figure, a connection passage 70 is secured tothe upper wall 9a of the water tank so as to open into the inverseU-shaped passage 52. A water reservoir 71 of a small diameter isconnected to the connection passage 70. The upper portion of thereservoir 71 is connected to the gas passage 16 similar to those in thedescribed embodiments. The electrode 22 of the liquid level meter 21 isinserted into the water reservoir 71. The operation of the liquid levelmeter 21 is the same as that in the described embodiments. In operation,for the purpose of bringing both water tanks 1,10 into communicationwith each other, the water is made to rise to the level of the waterreservoir 71. Since the water reservoir 71 has a comparatively smalldiameter, any fluctuation in the liquid level can be detected even by asensor having a comparatively low sensitivity. When two adjacent watertanks 1, 10 are brought into communication with each other as in thisembodiment, it is possible to arrange such that the water fills thepassage up to the top wall of the communication passage. In this case,the cross-sectional area of the communication passage is alwaysmaintained constant and, therefore, the flow resistance also ismaintained constant, whereby a stable flow of water is maintained andfluctuation in water levels in the associated water tanks can besuppressed. By arranging such that the water surface in the waterreservoir can be visually checked from the exterior, the states ofcommunication, i.e., whether the communication is interrupted orestablished can conveniently be confirmed visually.

FIG. 12 shows an embodiment in which the principle of the arrangementshown in FIG. 11 is applied to the arrangement shown in FIG. 4. Thus,the same reference numerals are used in this Figure to denote the sameparts or members as those appearing in FIG. 4, and the detaileddescription thereof is omitted. In this embodiment, the housing 5 isprovided with a pump-up pipe 75 which extends upward and the gas passagepipe 16 is connected to this water pump-up pipe 75. In addition, theelectrode 22 of the liquid level meter 21 is inserted into the waterpump-up pipe 75. For the purpose of establishing communication betweenthe water tanks 1 and 10, the water is pumped up to fill the waterpump-up pipe 75. This arrangement offers the same advantages as thoseoffered by the embodiment shown in FIG. 11. The embodiments shown inFIGS. 7 to 12 also conduct the interruption of the communication byapplying pressure, while the establishment of communication is effectedby the introduction of vacuum. The embodiments shown in FIGS. 7 to 12,which has an opening for mounting the liquid level meter 21 on the floorimmediately above the heat accumulation tank system offers an advantagethat the maintenance of the liquid level meter can be facilitated.

In the embodiments described hereinbefore, the connection between twoadjacent water tanks are provided above the normal water level in thewater tanks. The communication between both tanks is usually interruptedand the liquid level is raised in response to introduction of vacuum tofill up the connection, thereby establishing the communication betweentwo tanks. This arrangement, however, is not exclusive.

A description will be made herein under as to embodiments in which theconnection between two adjacent water tanks is positioned below thenormal water level in both water tanks

FIGS. 13 to 16 correspond to FIGS. 2 to 5. The riser pipe 13 in theembodiment shown in FIG. 13, the pipe 25 in the embodiments shown inFIGS. 14 and 15, and the upper end of the partition wall 28 in theembodiment of FIG. 16, respectively, are positioned at a level below thenormal water level H in both water tanks 1, 10. Thus, both water tanks1, 10 are communicated with each other in normal state. As schematicallyshown in FIG. 13, a gas passage 16 connected to the control chamber 24is connected also to a compressor 80 through a solenoid valve 18. Whenthe solenoid valve 18 is opened, compressed air from the compressor 80is introduced into the control chamber 24, so that the liquid level inthe control chamber is lowered to a level below the upper end of theriser pipe 13, as indicated at L, whereby the communication between bothwater tanks 1, 10 is interrupted. Although not shown in FIGS. 14 to 16,the embodiments shown in these Figures have similar constructions.

FIG. 17 illustrates an embodiment which corresponds to FIG. 6. Thedifference between the embodiment shown in FIG. 6 and that shown in FIG.17 resides in that the inverse U-shaped pipe 29 is positioned below thenormal water level WL in the water tanks 1,10. In this embodiment, thegas passage 16 is connected to the compressor 80 through the solenoidvalve 18.

FIG. 18 is a plan view of an example of the heat accumulation tanksystem to which the present invention is applied. The heat accumulationtank system 101 is sectioned into a plurality of water tanks 102 bymeans of partition walls such as anti-earthquake concrete walls. Thesewater tanks 102 are grouped suitably to form blocks A, B and C of thewater tanks. In each block, the adjacent water tanks 102 are mutuallyconnected through a communication pipe 104. A pipe 105 for pumping waterup from the water tank and for returning the water into the same isprovided in each block. A communication control device 106 in accordancewith the present invention is provided between adjacent blocks of thewater tanks. Some water tanks 102 are provided therein with flowsettling plates 107 which are intended for preventing short-circuitingof flow of the water.

FIGS. 19 to 23 illustrates the state of seasonal operation of the heataccumulation tank system. All the water tanks 102 of the blocks A, B andC are illustrated as being developed laterally. FIG. 19 illustrates thestate of operation in mid summer. In this case, all the water tanks 102of all the blocks A, B and C take part in the cooling. Thus, thecommunication control device 106 between adjacent blocks operate toestablish and maintain communication between these blocks.

Water is returned to one of the water tanks 102 in the block A and ismade to pass through the successive water tanks in the block A to comeinto the water tank in the block B. The water then flows through thesuccessive water tanks in the block B and then through the successivewater tanks 102 in the block C. The water is then pumped up from thefinal water tank 102 in the block C. Levels of the water in thesuccessive water tanks 102 vary in amount corresponding to the flowresistance encountered with the water flowing through adjacent watertanks 102.

FIG. 20 illustrates the state of operation in, for example, May orSeptemper. In this case, chilled water is stored in the water tanks 102of the block A and the block B for the purpose of cooling air. In thiscase, therefore, the communication control device 106 between the blocksA and B operates to establish and maintain communication therebetween,while the communication control device 106 between the blocks B and Coperates to interrupt the communication therebetween. FIGS. 21 and 22show the state of operation in, for example, April and November or Marchand November. In the state shown in FIG. 21, the communication controldevices 106 between the blocks A and B and between the blocks B and Cinterrupt the communication between these blocks, so that only the watertanks 102 in the block A takes part in the cooling. In FIG. 22, thecommunication control devices 106 between the blocks A and B and betweenthe blocks B and C operate to interrupt the communications, and thewater tanks 102 of the block A is used for cooling air, while the watertanks in the block A is used for the purpose of heating air.

FIG. 23 illustrates the state of operation in winter season. Thecommunication control device 106 between the blocks A and B is held ininterrupting state, while the communication control device 106 betweenthe blocks B and C allows the blocks B and C to communicate with eachother, so that the water tanks 102 in the block 102 are used for coolingpurpose, while the water tanks 102 in the blocks B and C are used forheating purpose. In the states shown in FIGS. 20 to 22, the tanks 102 ofthe block which are not being used may be drained for the purpose ofinspection of the tank interior. The draining of the water tanks 102 ofthe block A can be conducted by operating the communication controldevices 106 to shut-off the communication and, instead of the state ofuse as shown in FIG. 21, chilled water is stored in the water tanks ofthe block 102. FIG. 24 shows the state of the system in which the watertanks 102 in the block A have been drained.

When the communication control device of the present invention is usedbetween a water tank which is drained and a water tank which is notdrained as in the case of the water tank of the block A and the watertank of the block B in the operating state shown in FIG. 24, it isadvantageous to use the communication control device of the type whichnormally interrupts the communication and recovers the communicationunder action of a vacuum, as in the embodiments shown in FIGS. 1 to 12.

To explain in more detail in this connection, assuming the embodimentshown in FIG. 13 is used as the communication control device 106 in thesystem shown in FIG. 24, the control chamber 24 is brought intocommunication with the air in the water tank 1 when the water level inthe water tank 1 of the block A has come down below the level of theupper edge of the opening 4, thus disabling the control of the pressurein the control chamber 24. In this state, it is impossible to interruptthe flow of water in the control chamber 24, so that the water in thewater tank 10 of the block B is discharged into the tank 1 through thepipe 13. This flow is continued until the water level in the water tank10 is reduced to the level of the upper end of the riser pipe 13.Consequently, the water level in the water tanks in the block B islowered when the water tanks of the block A are drained. This means thatthe water in the water tanks of the block B is wasted and that thevolume of water which can be used in the water tanks of the block B isreduced to decrease the capacity of heat accumulation Thus, thisarrangement is quite uneconomical Usually, the heat accumulation tanksystem is provided with suitable means for maintaining water level inthe water tanks in order to ensure sufficient heat accumulation capacityand stable operation. If the operation of the system has to be continuedwith the water level in the tanks of the block B, therefore, it isnecessary to provide separate water level control means which maintainsthe lower water level, thus requiring a complicated control of the heataccumulation tank system.

In contrast, in the embodiment shown in FIG. 2, the upper end of theriser pipe 13 is positioned above the normal water level in the watertanks 1, 10, so that the reduction of water level in a tank or tanks ofany block does not affect the water levels in the tanks of other blocksin the shut-off condition realized by establishment of the atmosphericpressure in the control chamber 24. This also is true with otherembodiments shown in FIGS. 3 to 12, so that the above-describeddisadvantages from the view points of economy and controller are alleliminated.

In the state of use of the system as shown in FIG. 23, a considerablylarge difference of water level is developed between the downstream endwater tank 102 of the block A and the upstream end water tank 102 of theblock B, in the state in which the communication is interrupted. It isto be understood that the use of the communication control device of thetype shown in FIGS. 1 to 12, which normally shuts off the communicationand recover the communication under action of vacuum, is a specificallyadvantageous in the case where a large difference of the water level isdeveloped between the adjacent water tanks which are connected throughthe communication control device.

This fact will be explained in more detail through an embodiment. It isassumed here that the communication control device of the type shown inFIG. 13 is used which normally provides communication and interrupts thecommunication under the action of positive pressure. In such a case, itis preferred that air is suitably blown into the control chamber so asto maintain a constant water level in the control chamber, in order tomake up for the leakage of the gas during interruption of communication.In such a case, a certain problem is encountered in regard to the levelof the water in the control chamber. In the embodiment shown in FIG. 13,if a difference of water level is caused between the water tanks 1 and10 such that the water level in the water tank 10 is higher than that inthe water tank 1 by a height h while both tanks 1 and 10 aredisconnected from each other, the water level around the riser pipe 13rises in the control chamber 24, while the water level in the riser pipe13 comes down, with the result that a level difference h is establishedbetween the interior and the exterior of the riser pipe.

In the embodiment shown in FIG. 13, the pressure in the control chamber24 is controlled upon detection of the water feel outside the riser pipe13 in the control chamber 24, so that the above-mentioned rise in thewater level around the riser pipe 13 is sensed by the liquid levelmeter, whereby the pressure in the control chamber 24 rises by amountcorresponding to the rise in the water level. As a result, the waterlevel in the control chamber 24 is further reduced so that air is blowninto the water tank 1. In order to avoid such a direct blowing of airinto the water tank, it is necessary to conduct a highly complicatedcontrol. This is quite inconvenient from the view point of economy.

In contrast, in the embodiment shown in FIG. 2, the control chamber isheld in communication with the atmosphere when the communication deviceinterrupts the communication, so that it is not necessary to control thepressure in the control chamber. Thus, the above-mentioned problem caneasily be overcome simply by setting the upper end of the riser pipe 13at a level which is determined by taking into consideration the possiblerise of the water level in the water tank 10. In the embodiment of thetype in which the communication is established by the application of anegative pressure, an easy detection of the water level is realized byproviding a water reservoir or the water pump-up pipe as in theembodiments shown in FIGS. 11 and 12.

Thus, in some uses of the communication control apparatus of theinvention, the device of the type which establish communication byapplication of vacuum produces a greater effect than the device of thetype which interrupts the communication by application of pressure.

INDUSTRIAL APPLICABILITY

The communication control device of the present invention does not needany movable part to be disposed in the liquid part so that it is almostfree from the problems such as operation failure and breakdown or wearof the parts. In consequence, the work for the protective maintenancecan be reduced remarkably. Furthermore, it becomes possible to realize aremote control by suitably elongating the gas passage. In addition, itbecomes possible to make an efficient use of a restricted area in thebuilding or the like, because it is not necessary to preserve a largespace on the floor immediately above the heat accumulation chamber forthe purpose of installing the valve operating mechanism or a large areafor the protective maintenance.

What is claimed is:
 1. In a heat accumulation tank system having aplurality of water tanks which are separated by partition walls, acommunication control device for controlling the state of communicationbetween adjacent two water tanks of said system, comprising: a controlchamber connected to one of said two adjacent water tanks and closed atleast upper side thereof; a passage having one end opening in the otherof said two adjacent water tanks and the other end which rises throughsaid control chamber so as to open in said control chamber at a levelabove the normal water level in said water tanks; a vacuum section meansconnected to an upper portion of said control chamber through a valvemeans; a through pipe provided on the upper side of said control chamberand having one end opening in said control chamber while the other endis closed at a level higher than the top wall of said heat accumulationtank system; and a liquid level sensor provided in said control chamberthrough said through pipe.
 2. A communication control device accordingto claim 1, further comprising a gas passage connected to said throughpipe and leading to a pressure control means.
 3. In a heat accumulatingtank system having a plurality of water tanks separated by partitionwalls, a communication control device for controlling the state ofcommunication between two adjacent water tanks of said system,comprising: an inverse U-shaped passage having one end opening in one ofsaid two water tanks and the other end opening in the other of said twowater tanks; pressure controlling means for controlling the pressure inthe upper portion of said inverse U-shaped passage; a through pipeprovided on the upper side of said inverse U-shaped passage and havingone end opening in said inverse U-shaped passage while the other end isclosed at a level higher than the top wall of said heat accumulationtank system; and a liquid level sensor provided in said inverse U-shapedpassage through said through pipe.
 4. A communication control deviceaccording to claim 3, wherein said passage is disposed such that theintermediate portion thereof is disposed above the normal water level insaid water tanks while both ends thereof are disposed below said waterlevel, and said pressure control means is constituted by vacuum suctionmeans connected to an upper portion of said inverse U-shaped passagethrough a valve means.
 5. A communication control device according toclaim 3, wherein said passage is disposed such that its whole portion isdisposed below the normal water level in said water tanks, and whereinsaid pressure control means includes a compressor connected to an upportion of said inverse U-shaped passage through valve means.
 6. Acommunication control device according to claim 3, further comprising agas passage connected to said through pipe and leading to a pressurecontrol means.
 7. In a heat accumulating tank system having a pluralityof water tanks separated by partition walls, a communication controldevice for controlling the state of communication between two adjacentwater tanks of said system, comprising: a control tank defining in oneof said two adjacent water tanks a closed control chamber; a riser pipehaving one end opened to the outside of said control tank at a levelbelow the normal water level in one of said two adjacent water tanks andthe other end rising through said control tank so as to open at itsupper end in an upper portion of said control chamber; a passage throughwhich said control chamber is connected to the other of said twoadjacent water tanks; and pressure control means for controlling thepressure in an upper portion of said control chamber.
 8. A communicationcontrol device according to claim 7, further comprising a through pipedisposed above said control chamber and having one end opened in saidcontrol chamber while the other end is closed at a level above the topwall of said heat accumulation tank system, and a liquid level sensorprovided in said control chamber through said through pipe.
 9. Acommunication control device according to claim 8, further comprising agas passage connected to said through pipe and leading to said pressurecontrol means.
 10. A communication control device according to claim 7,further comprising a water reservoir connected to said control chamber,a gas passage connected to an upper portion of said water reservoir andleading to a vacuum suction means, and a liquid level sensor provided insaid water reservoir.
 11. In a heat accumulating tank system having aplurality of water tanks separated by partition walls, a communicationcontrol device for controlling the state of communication between twoadjacent water tanks of said system, comprising: a control tank disposedin one of said two adjacent water tanks and closed at least the upperside thereof and opened an its lower side to said one of said twoadjacent water tanks; a passage having one end opened to the other oftwo adjacent water tanks while the other end rises through said controltank so as to open at its upper end to an upper portion of a controlchamber in said control tank; and a pressure control means forcontrolling the pressure in the upper portion of said control chamber.12. A communication control device according to claim 11, furthercomprising a through pipe disposed above said control chamber and havingone end opened in said control chamber while the other end is closed ata level above the top wall of said heat accumulation tank system, and aliquid level sensor provided in said control chamber through saidthrough pipe.
 13. A communication control device according to claim 12,further comprising a gas passage connected to said through pipe andleading to a pressure control means.
 14. A communication control deviceaccording to claim 11, further comprising a water reservoir connected tosaid control chamber, a gas passage connected to an upper portion ofsaid water reservoir and leading to a vacuum suction means, and a liquidlevel sensor provided in said water reservoir.
 15. In a heataccumulating tank system having a plurality of water tanks separated bypartition walls, a communication control device for controlling thestate of communication between two adjacent water tanks of said system,comprising: a control chamber disposed in one of said two water tanksand closed at its upper side; a partition means for dividing theinterior of said control chamber into a first chamber and a secondchamber; an opening through which said first chamber is opened to one ofsaid two water tanks; a passage through which said second chamber isconnected to the other of said two water tanks; and pressure controlmeans for controlling the pressure in the upper portion of said controlchamber.
 16. A communication control device according to claim 15,further comprising a through pipe disposed above said control chamberand having one end opening in said control chamber while the other endis closed at a level above the top wall of said heat accumulation tanksystem, and a liquid level sensor provided in said control chamberthrough said through pipe.
 17. A communication control device accordingto claim 16, further comprising a gas passage connected to said throughpipe and leading to a pressure control means.
 18. A communicationcontrol device according to claim 15, further comprising a waterreservoir connected to said control chamber, a gas passage connected toan upper portion of said water reservoir and leading to a vacuum suctiondevice, and a liquid level sensor provided in said water reservoir. 19.In a heat accumulation tank system having a plurality of water tanksseparated by partition walls, a communication control device forcontrolling the state of communication between two adjacent water tanksin said system, comprising: passage forming means disposed to bridgeover said partition wall between said two adjacent water tanks andforming between said two adjacent tanks an inverse U-shaped passagewhich provides communication between said two adjacent water tanksbridging over said partition wall; pressure controlling means forconnecting the upper portion of said inverse U-shaped passage to avacuum suction means through valve means; a through pipe provided abovesaid inverse U-shaped passage and having one end opened to said inverseU-shaped passage while the other end is closed at a level above the topwall of said heat accumulation tank system; and a liquid level sensorprovided in said inverse U-shaped passage through said through pipe. 20.A communication control device according to claim 19, wherein saidpassage forming means is provided on the top wall of said heataccumulation tank system.
 21. A communication control device accordingto claim 19, wherein said passage forming means is provided on a coverwhich is detachably secured to the top wall of said heat accumulationtank system.
 22. A communication control device according to claim 19,further comprising a gas passage connected to said through pipe andleading to a control means.
 23. A communication control device accordingto any one of claims 19 to 21, further comprising a through pipedisposed above said control chamber and having one end opened in saidcontrol chamber while the other end is closed at a level above the topwall of said heat accumulation tank system, and a liquid level sensorprovided in said control chamber through said through pipe.
 24. Acommunication control device according to claim 23, further comprising agas passage connected to said through pipe and leading to a pressurecontrol means.
 25. A communication control device according to any oneof claims 19 to 21, further comprising a water reservoir connected tosaid control chamber, a gas passage connected to an upper portion ofsaid water reservoir and leading to a vacuum suction device, and aliquid level sensor provided in said water reservoir.
 26. In a heataccumulation tank system having a plurality of water tanks separated bypartition walls, a communication control device for controlling thestate of communication between two adjacent water tanks in said system,comprising: a control tank closed at least at its upper side thereof andopening at its lower side to one of said two adjacent water tanks; apassage having one end opened to the other of said two adjacent watertanks and the other end rising through said control tank so as to openat its upper end to an upper portion of a control chamber in saidcontrol tank; and pressure control means for pressurizing the space inupper portion of said control chamber so as to interrupt thecommunication between said two adjacent water tanks and for introducingvacuum to said upper portion of said control chamber so as to establishcommunication between said two adjacent water tanks.
 27. A communicationcontrol device according to claim 26, wherein said passage opens to anupper portion of said control chamber at a level near the normal waterlevel in said water tanks.
 28. A communication control device accordingto claim 26 or 27, wherein said control tank is disposed in one of saidtwo adjacent water tanks.
 29. A communication control device accordingto claim 26 or 27, wherein said control tank is disposed in the other ofsaid two adjacent water tanks.
 30. A communication control deviceaccording to claim 26, further comprising a through pipe disposed abovesaid control chamber and having one end opened in said control chamberwhile the other end is closed at a level above the top wall of said heataccumulation tank system, and a liquid level sensor provided in saidthrough pipe through said through pipe.
 31. A communication controldevice according to claim 30, further comprising a gas passage connectedto said through pipe and leading to a pressure control means.
 32. Acommunication control device according to claim 26 further comprising awater reservoir connected to said control chamber, a gas passageconnected to an upper portion of said water reservoir and leading to avacuum suction device, and a liquid level sensor provided in said waterreservoir.
 33. In a heat accumulation tank system having a plurality ofwater tanks separated by partition walls, a communication control devicefor controlling the state of communication between two adjacent watertanks in said system, comprising: an inverse U-shaped passage disposedbetween said two adjacent water tanks such that one end of said inverseU-shaped passage opens in one of said two adjacent water tanks while theother end opens in the other of said two adjacent water tanks; andpressure control means for applying a pressure to the space in upperportion of said inverse U-shaped passage so as to interrupt thecommunication between said two adjacent water tanks and for applying anegative pressure to said space in upper portion of said inverseU-shaped passage so as to establish communication between said twoadjacent water tanks.
 34. A communication control device according toclaim 33, further comprising a through pipe disposed above said inverseU-shaped passage and having one end opened in said inverse U-shapedpassage while the other end is closed at a level above the top wall ofsaid heat accumulation tank system, and a liquid level sensor providedin said inverse -shaped passage through said through pipe.
 35. Acommunication control device according to claim 34, further comprising agas passage connected to said through pipe and leading to said pressurecontrol means.
 36. A communication control device according to claim 33,further comprising a water reservoir connected to said inverse U-shapedpassage, a gas passage connected to an upper portion of said waterreservoir, and a liquid level sensor provided in said water reservoir.37. A method of controlling the operation of a heat accumulation tanksystem having a plurality of water tanks separated by partition walls,comprising: grouping said water tanks into a plurality of blocks eachhaving at least one said water tank; allowing said water tanks of thesame block to communicate each other, providing a communication devicebetween each adjacent blocks; said communication device having acommunication passage provided with a portion which can be charged witha gas; and selectively charging and discharging a gas to and from saidportions of said communication passages, whereby the passage of water insaid heat accumulation tank system and/or the number of blockscommunicated is varied in accordance with the level of the thermal loadapplied to said heat accumulation tank system.